In many biological applications, it is desirable to rupture microparticles so that their contents can be analyzed, or to identify or characterize intact microparticles. For instance, there is great interest in the development of cost effective and rapid methods for monitoring the presence and concentration of bacterial or other cells in military, medical, agricultural and food preparation applications. The analysis of cells often requires that they be ruptured, so that the contents of the cells can be analyzed. For certain microparticle types, however, rupturing is problematic.
For instance, when stressed or starved for nutrients, vegetative bacterial cells can differentiate into dormant endospores, more commonly referred to as spores. Spores are highly resistant to inactivation and rupture by various physical treatments, including mechanical agitation, ultraviolet and gamma radiation, heat, and chemical treatments. The need for bulky complex equipment, such as microwave or ultrasonic instrumentation, to accomplish rupturing, adds significantly to the cost, and decreases the speed, of detecting and analyzing such cells. In addition, the harsh conditions presently used for rupturing can inadvertently damage the contents of the cells. For example, rupture via the chemical action of surfactants, or the physical stress provided by sonication, can damage or denature DNA, protein, or other components in the cell. Similar concerns exist for the analysis of non-biological microparticles.
The present invention overcomes these problems by providing an apparatus that uses nanostructured surfaces to facilitate the rupture or testing of microparticles, as well as methods of using and making such an apparatus.